CNTN1 and nephrotic syndrome: Laboratory investigations revealed nephrotic syndrome while renal biopsy showed thickening of the basement membrane along with glomerular IgG4 deposits and local subepithelial projections consistent with MN. Autoantibody assays detected IgG4 and IgG1 anti-CNTN1 antibodies; however, anti-NF155, anti-PLA2R, and anti-THSD7A antibodies were not detected. Sjögren's syndrome was also identified in the patient on the basis of elevated anti-SSA/Ro antibodies and pertinent clinical features.